1. Field of the Invention
This invention relates to a multicolor developing devices, and, more particularly, to multicolor developing devices of the type in which magnetic developing particles retained by magnetic forces are caused to adhere to an electrostatic latent image to thereby develop the same into a visible image in multicolor.
2. Description of the Prior Art
A developing unit of the type in which a magnetic roller is rotatably supported within a non-magnetic sleeve and magnetic developing particles are carried along the outer periphery of the sleeve by the magnetic forces produced by the magnetic roller to be adhered to an electrostatic latent image formed on a recording sheet is disclosed in U.S. Pat. No. 3,455,276 granted to Glenn R. Anderson July 15, 1969 (Assignee, Minnesota Mining and Manufacturing Company; Filed, May 23, 1967, Ser. No. 640,720). A plurality of such developing units will be required if in a copying machine it is desired to develop an electrostatic latent image in multicolor or in any desired color. Such a copying machine will be constructed such that one of the developing units developers containing developing particles of any desired color therein is brought to the developing position to perform developing.
In the meantime it is desirable that the respective developing units be arranged in equidistant spaced relation with the electrostatic latent image forming station and the developing station. The reason for this is that it is preferable to keep constant the time required for conveying a recording sheet to the developing station after the formation of electrostatic latent images to thereby make the amount of leakage of the static charge equal for all the colors. Also, when a plurality of developing units are used, it is essential to make a developing apparatus compact in size by reasonably arranging the developing units.